Re: st: Inequality constraint with mata -optimize-

Thanks, Stas. I am using ML to estimate a disequilibrium model, in
which the likelihood function is set up as in Maddala and Nelson,
"Maximum Likelihood Methods for Models of Markets in Disequilibrium,"
Econometrica, 1974. I simply want to constrain two of the parameters
-- variances of the error terms in the demand and supply equations --
to be greater than or equal to zero.
Many thanks,
Dorothy
On Sun, May 29, 2011 at 3:17 PM, Stas Kolenikov <skolenik@gmail.com> wrote:
> On Sun, May 29, 2011 at 2:42 PM, Dorothy Bridges <dbstata@gmail.com> wrote:
>> I'd like to constrain two parameters to be greater than zero. I
>> understand the Cc syntax for linear equality constraints, but I'm not
>> sure how to code Cp'>=C. Thanks very much in advance for your help.
>
> Describe your problem in more detail, please. Inequality constraints
> on parameters make for a rather complicated inference with weird
> asymptotic distributions, so you'd be better very much aware that you
> are doing the right thing.
>
> --
> Stas Kolenikov, also found at http://stas.kolenikov.name
> Small print: I use this email account for mailing lists only.
>
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/